This disclosure relates to a medical device and more particularly to a catheter used to deliver a therapeutic substance.
The medical device industry produces a wide variety of electronic and mechanical devices for treating patient medical conditions. Depending upon medical condition, medical devices can be surgically implanted or connected externally to the patient receiving treatment. Clinicians use medical devices alone or in combination with therapeutic substance therapies and surgery to treat patient medical conditions. For some medical conditions, medical devices provide the best, and sometimes the only, therapy to restore an individual to a more healthful condition and a fuller life. One type of medical device is a catheter used to deliver a therapeutic substance.
Catheters are used to deliver a therapeutic substance from a source such as a therapeutic substance deliver device to a desired infusion site. Therapeutic substance delivery devices are also known as drug pumps and drug delivery devices can be located external to a patient or implanted within the patient. An example of a therapeutic substance delivery devices is a SynchroMed(copyright) Infusion System available from Medtronic, Inc. which includes a Model 8709 InDura catheter. Catheters can be partially inserted or implanted in a patient or fully implanted with the proximal end connected to a therapeutic substance delivery device and the distal end located near the desired infusion site. Catheter delivered therapeutic substances are typically used to treat a condition that responds to a therapeutic substance delivered directly to an infusion site in the body rather than being ingested. Catheters can be employed to treat conditions such as pain, spasticity, cancer, infections, gene abnormalities, and the like.
Catheters are typically configured with infusion rate openings fixed when the catheter is manufactured. Some catheters have a single opening at the distal end of the catheter, so the infusion rate is essential the same as the therapeutic substance deliver device infusion rate. Some catheters have more than one opening that can be configured near the catheter distal end or along the length of the catheter.
For the foregoing reasons, there is a need for a variable infusion rate catheter that permits a clinician to adjust the catheter""s infusion rate before use and during use to make the catheter more versatile in treating medical conditions and have many other improvements.
The variable infusion rate catheter has a Micro Electro Mechanical System (MEMS) variable flow restriction fluidly coupled to the catheter to make the catheter more versatile and provide many other improvements. The variable infusion rate catheter permits a clinician to change the infusion rate either before the catheter is placed at an infusion site or after the catheter has been placed at an infusion site. The MEMS variable flow restriction is adjustable to vary the infusion rate from at least one catheter infusion opening. More than one MEMS variable flow restrictions can be used with a catheter to permit the catheter to have different infusion rates at different infusion openings. The catheter is coupleable to a therapeutic substance delivery device and configured to deliver therapeutic substance to a single or multiple delivery sites in a body. Many embodiments of the variable infusion rate catheter and its methods of operation are possible.